A. Field of Invention
This invention pertains to the art of methods and apparatuses of bowstring drawing devices and even more particularly, to the art of methods and apparatuses of portable cocking devices for drawing a bowstring of a crossbow.
B. Description of the Related Art
It is known to increase the speed and accuracy at which a projectile is propelled from an archery device is to increase the stiffness of the outwardly extending bow limbs. However, increasing the stiffness of the outwardly extending bow limbs results in an increase in the effort or force required when pulling or drawing the bowstring into position for firing. At some point, simply increasing the stiffness of the outwardly extending bow arms becomes counterproductive since users do not have the physical strength to pull back or draw the bowstring into position for firing and maintain this position until the user has sighted his or her target and is ready to release the bowstring. Furthermore, if the user is struggling to maintain the drawn position of the bowstring, his or her aim will be negatively affected.
In a crossbow, a longitudinally extending main beam, commonly called the stock, includes a trigger mechanism which holds the bowstring in the drawn position, allowing the user to sight a target without manually holding and maintaining the draw weight. This allows the stiffness of the bow limbs to be increased significantly, and modern crossbows can have bowstring pull weights of 150 pounds or more. Although the trigger maintains the drawn position of the bowstring, drawing the bowstring into engagement with the trigger mechanism is still very difficult. It is readily apparent that with high pull weights, even operating a crossbow could be difficult, if not impossible, for many users having limited physical strength. This is particularly true for target practice or other situations where the crossbow is cocked numerous times.
In order to draw the crossbow bowstring and cock the crossbow, the user must have sufficient physical strength to draw the full bowstring draw weight of the crossbow. Devices have been used in conjunction with crossbows to make this cocking operation easier for users to accomplish. For example, some crossbows include a stirrup, which is mounted to one end of the crossbow. In such crossbows, the user places the stirrup onto the ground and places a foot onto the stirrup to support the crossbow for cocking. By applying the user's body weight to the grounded stirrup, the user can draw the crossbow bowstring into cocked position. Although helpful, this provides only limited advantage. In addition, it is very difficult to properly draw the bowstring in a manner that the limbs are each tensioned to the same degree, or the bow is drawn in a balanced manner relative to the outwardly extending limbs of the crossbow such that when the bowstring is released from the crossbow trigger mechanism, an equalized force will be imparted to the projectile or arrow positioned therein. This balancing of the forces imparted on the bowstring by means of the crossbow limbs is particularly important for shooting accuracy in using the crossbow, and also adds to safety of use.
Although known crossbow bowstring cocking devices work well for their intended purpose, conventional manual crank winch devices and leverage-type cocking devices are often large, heavy, and cumbersome and commonly must be connected and disconnected from the crossbow with each use. In many cases instead of simplifying the cocking procedure, these known devices add complexity or cost, are too cumbersome to handle and use effectively, and/or fail to ensure that the bowstring is drawn in a balanced manner. It remains desirable to develop cocking devices that are small, light, or not cumbersome, or which draw the bowstring in a balanced manner.